121 Walkability Index address methodology — v1

The input coordinate is used ephemerally to find the nearest eligible pedestrian-network point. The published record does not retain an address or coordinate.

An administrative boundary, incorporated-place status, place-name centroid, residential grid, and area median are not used. A routable address in an unincorporated community is evaluated the same way as a routable address in a city.

• The address and each destination may use a straight snap leg of at most 120 meters to reach the pedestrian network.
• If the address cannot snap to an eligible network component of at least 20 nodes, the score is withheld.
• No straight-line destination distance substitutes for a missing pedestrian route.

The address-v1 categories are Groceries, Dining, Coffee, Shopping/errands, Parks/recreation, Schools, and Transit stops, with the same published weights as area methodology v2.

Full category credit requires three nearby options because destination rank weights are 1, 0.5, and 0.25. One full-credit option earns 1 ÷ 1.75, or about 57%, of its category.

Each category receives full distance credit through 0.25 walking miles, followed by linear decay to zero at 30 modeled walking minutes.

• Permanently closed, low-confidence, unknown-taxonomy, and same-category colocated duplicates are excluded.
• At least four routed amenity categories are required for a numeric score.
• Every category reports its nearest routed distance, counted choices, credit, and weighted points.

A bounded 0.90–1.10 street-form multiplier uses the connected pedestrian network within 800 routed meters of the address plus a 120-meter analysis halo.

The fixed local radius prevents an address score from changing merely because an otherwise irrelevant regional extract is larger or smaller.

• Measured inputs are intersection rate, average eligible edge length, and connected-component coverage.
• The address snap distance, connected-component size, local radius, halo, and aggregate snap-leg provenance accompany the score.

Every build verifies a pinned Overture release manifest and checksums for places and transportation records.

The index measures modeled access, not sidewalk condition, personal mobility, crime, safety, comfort, temporary closures, destination quality, or school assignment.

Address-v1 does not adjust walking time for elevation or slope, so hillside routes can feel more difficult than the modeled distance implies.

Version address-v1 is permanent. Later address methodology changes receive a new versioned URL; this page is not silently rewritten into a different method.

• Overture sources are checked monthly and candidate extracts remain immutable and reproducible.
• A missing category is shown as zero options; a missing network or inadequate source coverage suppresses the entire score.

• Overture Maps Foundation attribution
• OpenStreetMap copyright and ODbL

Machine-readable document: /methodology/121-walkability-index/address-v1.json.